Answer is: from strongest to weakest attractions: ionic forces, covalent forces, hydrogen forces, Van der Waals forces.
Ionic bond is the electrostatic attraction between oppositely charged ions; ionic bond is very strong.
For example, sodium chloride (NaCl) has ionic bond between sodim cation and chlorine anion.
Covalent bond is bond between nonmetals. Hydrogen and oxygen are nonmetals.
For example, in water, atoms of hydrogen (H) and oxygen (O) are connected by polar covalent bonds.
Hydrogen bond is an electrostatic attraction between two polar groups that occurs when a hydrogen atom (H), covalently bound to a highly electronegative atom such as flourine (F), oxygen (O) and nitrogen (N) atoms.
For example, because of hydrogen bonds, water has higher melting and boiling temperatures than H₂S.
There are two kinds of Van der Waals forces: weak London dispersion forces and stronger dipole-dipole forces.
They are all part of the ammonium ion (NH4) of which there are 3 in the molecule.
So the number of hydrogen atoms = 4 * 3 = 12.
Answer:
C. The reaction can be broken down and performed in steps
Explanation:
Hess's Law of Constant Heat Summation states that irrespective of the number of steps followed in a reaction, the total enthalpy change for the reaction is the sum of all enthalpy changes corresponding to all the steps in the overall reaction. The implication of this law is that the change of enthalpy in a chemical reaction is independent of the pathway between the initial and final states of the system.
To obtain MgO safely without exposing magnesium to flame, the reaction sequence shown in the image attached may be carried out. Since the enthalpy of the overall reaction is independent of the pathway between the initial and final states of the system, the sum of the enthalpy of each step yields the enthalpy of formation of MgO.
A supposition or proposed explanation made on the basis of limited evidence as a starting point for further investigation